Industrial controllers are special-purpose computers utilized for controlling industrial processes, manufacturing equipment, and other factory automation, such as data collection or networked systems. Controllers often work in concert with other computer systems to form an environment whereby a majority of modern and automated manufacturing operations occur. These operations involve front-end processing of materials such as steel production to more intricate manufacturing processes such as automobile production that involves assembly of previously processed materials. Often such as in the case of automobiles, complex assemblies can be manufactured with high technology robotics assisting the industrial control process.
In many automated processes, including the basic production of commodities such as food, beverages, and pharmaceuticals, complex state logic is often designed and programmed by Systems Engineers or provided in some cases by automated equipment manufacturers. This logic is often programmed with common PLC ladder logic or higher level languages supported by Sequential Function Charts. Sequence logic can be employed for a plurality of tasks such as material movement and conveying operations, packaging operations, or as part of an assembly process itself, wherein various stages of an assembly are sequenced from stage to stage until a final assembly occurs. As can be appreciated, much planning and design is required to implement an automated production process that can involve hundreds of machines, computers, and program logic to facilitate proper operation of the respective sequences.
In some batch systems for automating production processes, current batch products can aggregate Units for production into Unit Classes, where a Unit Class defines the global common functionality of all Units that are members of the Unit Class. This allows for the construction of “class-based” recipes, built against a Unit Class or Classes. When building a class based recipe, a recipe author is generally limited to referencing only the functionality common to all instances of the Unit Class. This generally results in the class based recipe being able to run against all instances of the Unit Class. The “common functionality” that can be referenced across all members of a Unit Class by class based recipes are Recipe Phases and Unit Tag Classes. However, variations in the properties (attributes) of the individual reactors are great enough that the set of properties (attributes) that are common to all instances of the class are limited. Recipe Phases can be employed as “steps” inside of Unit Operation Sequential Function Charts (SFCs), for example. Unit Tag Classes can be referenced by Transition Expressions on Transitions inside of class based Unit Procedure and Unit Operation SFCs.
One challenge facing industrial processing systems is related to how equipment resources are selected, acquired and prioritized for use given a set of competing resources that can be employed for a given operation. Presently, high-end controllers need to analyze resources available, communicate with the resources, and determine which resource should be selected based upon an arbitration routine. Such overhead and monitoring requires programming resources to be expended on the controller while lowering the overall performance of the controller. In extreme cases, a dedicated server may be employed to arbitrate priorities among resources. As can be appreciated, utilizing additional hardware and software can add considerable cost to a given control solution.